Automatic fluid operated spring loaded jack lock assembly

ABSTRACT

One or more spring-biased plungers supplement the action of fixed jacks in supporting a workpiece mechanically operated on forcibly in one way or another, as in a metalworking machine, to afford a distributed and rigid support of the workpiece at a plurality of locations therebeneath. The plunger is spring-urged upwardly, then clamped in an upwardly adjusted position by locking elements which are cam-actuated toward one another in opposite horizontal directions. As thus automatically clamped in a positive preliminary way, a fluid pressure-operated piston wedge device comes into action beneath the plunger sub-assembly to rigidly sustain the same through completion of the metalworking operation.

United States Patent [191 Claycomb Jan.7, 1975 AUTOMATIC FLUID OPERATED SPRING LOADED JACK LOCK ASSEMBLY [76] Inventor: Dean A. Claycomb, 3921 W.

Townhall Rd, Traverse City, Mich. 49684 [22] Filed: Aug. 10, 1973 21 Appl. No.: 387,484

[52] US. Cl 269/27, 269/296, 269/310 [51] 1nt.Cl B23q 3/10 [58] Field of Search 269/20, 24, 32, 35, 221, 269/296, 309, 310, 27; 254/104 [56] References Cited UNITED STATES PATENTS 2,696,764 12/1954 Sternbergh, Sr. 269/310 3,537,701 11/1970 Claycomb 269/309 3,559,980 2/1971 Terai 269/20 FOREIGN PATENTS OR APPLICATIONS 951,978 3/1964 Great Britain 269/24 Primary Examiner-Granville Y. Custer, Jr. Assistant Examiner-Neil Abrams Attorney, Agent, or Firm-Whitternore, Hulbert & Belknap [57] ABSTRACT One or more spring-biased plungers supplement the action of fixed jacks in supporting a workpiece mechanically operated on forcibly in one way or another, as in a metalworking machine, to afford a distributed and rigid support of the workpiece at a plurality of locations therebeneath. The plunger is spring-urged up wardly, then clamped in an upwardly adjusted position by locking elements which are cam-actuated toward one another in opposite horizontal directions. As thus automatically clamped in a positive preliminary way, a fluid pressure-operated piston wedge device comes into action beneath the plunger sub-assembly to rigidly sustain the same through completion of the metalworking operation.

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AUTOMATIC FLUID OPERATED SPRING LOADED JACK LOCK ASSEMBLY CROSS-REFERENCE TO RELATED APPLICATION My copending application Ser. No. 387,482, filed Aug. 10, 1973, discloses a similar type of unit having a movable plunger device in which clamping and wedging components are operated under manual control.

BACKGROUND OF THE INVENTION 1. Field of the Invention The improvement of the invention finds wide application in many types of metalworking operations in which very heavy forces are applied on a workpiece and must be rigidly sustained without movement of the piece.

2. Description of the Prior Art My prior US. Pat. No. 3,547,701 of Nov. 3, 1970 discloses a generally similar workpiece supporting assembly operated under manual control; and my later US. Pat., No. 3,690,641 of Sept. l2, 1972 is even more particularly related to the present improvement, in that it discloses, particularly in FIGS. 6-11, inclusive, thereof, a fluid pressure-operated spring-loaded jack lock assembly, which in respect to certain structural features and sub-assemblies corresponds considerably to what is herein disclosed. Cleveland Reissue US. Pat. No. 23,732 of Nov. 10, 1953 and Johnson US. Pat. No. 1,254,044 of Jan. 22, 1918 show the use of a springbiased plunger in a work support; and Galbarini et al, US Pat. No. 3,362,295 of Jan. 9, 1968, Gecks et al, US. Pat. No. 2,829,566 of Apr. 8, 1958, McCann et al, US, Pat. No. 3,323,789 of June 6, 1967, and Tridgell US. Pat. No. 3,421,750 of Jan. 14, 1969 relate to supporting devices utilizing fluid pressure power. Lyon US. Pat. No. 1,438,250 of Dec. 12, 1922 and Sternbergh US. Pat. No. 2,696,764 of Dec. 14, 1954 utilize a simple type of wedge lock for a work support. I am unaware of other prior art more pertinent than the above.

SUMMARY OF THE INVENTION The improvement of the invention incorporates a pair of oppositely acting locking sleeves which are automatically operated toward one another in an axial direction by an anti-friction type of cam and follower sub-assembly, thus to clamp a spring-biased workpiece supporting plunger in place after it has taken supporting engagement beneath the piece. A laterally acting cam of said sub-assembly is operated for the intended locking sleeve action by a fluid pressure operated piston and cylinder unit. Hydraulic pressure acts on that unit, as well as upon a horizontal second piston of the assembly to cause a wedge surface on the latter piston to assume a wedging locked engagement beneath the workpiece supporting plunger and positively prevent a retrograde downward motion of the latter under heavy load. The pistons operate under the control of similar ball check-type cylinder inlet and bleeder valves.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view of a work table or fixture plate having fixed end supports and intermediate adjustable work supporting and locking devices for supporting a casting or workpiece which is illustrated in dotted lines;

FIG. 2 is a front elevational view of the fixture plate and related equipment illustrated in FIG. 1 with the casting being shown in dotted lines;

FIG. 3 is an end elevational view showing a portion of a locking device of the invention;

FIG. 4 is a top plan view partially broken away and in horizontal section on a line corresponding to line 4-4 of FIG. 5;

FIG. 5 is a view in vertical section on line 5-5 of FIG. 4;

FIG. 6 is a fragmentary view sectioned vertically on line 6-6 of FIG. 4;

FIG. 7 is a fragmentary side elevational view of the device, as from the left of FIG. 5;

FIGS. 8, 9 and 10 are vertical transverse sections on lines corresponding respectively to lines 8-8, 9-9 and 10-10 of FIG. 5;

FIG. 11 is a fragmentary view in transverse vertical section on line 11-11 of FIG. 7, showing a wedge cylinder bleeder ball check unit; and

FIG. 12 is a fragmentary view in horizontal section on line 12-12 of FIG. 7, showing another ball check detail governing hydraulic flow to the wedge cylinder.

DESCRIPTION OF A PREFERRED EMBODIMENT The assembly of the invention, as generally designated 10, comprises a horizontal work support table or fixture 12 shown in FIGS. 1 and 2 as having an upper flat surface 13, above which a casting or workpiece W to be machined is supported by three solid supports 14 mounted rigidly on the fixture plate, portions of which are shown in FIGS. 1 and 2. The top surfaces of the said supports are located in the same horizontal plane; and when the casting W is mounted. thereon it is in the proper and required plane for machining. It is necessary to support the intermediate portions of the cast workpiece W in order to prevent it from deflecting during the machining operation; and spring loaded jack assemblies 16 are provided for this purpose. In addition, the piece W may if desired be bolted to a pair of threaded posts, not shown, as is well known in the art. The top surfaces of buttons 17 fixed on operating plungers of the jack assemblies 16 engage the rough cast surfaces of the casting W to form a solid supplemental support for the latter after said plungers are locked in place. Thereafter, during milling, boring or other machining operations, the jacks 16 will prevent the intermediate portions of the casting W from de fleeting. Any number of such jacks or jack assemblies 16 may be used depending on the size of the casing W. The jacks 16 are connected by hydraulic lines 19 to a common pneumatically operated hydraulic pressure source 15, which is well known in the art, and is shown in FIG. 1.

FIGS. 3-7 illustrate the general construction of one of the three identical jacks 16 in specific detail. Each jack assembly 16 comprises an elongated body 20 bolted or otherwise fixedly secured to plate 12. The body 20 has a horizontal cylindrical bore 21 and a vertical cylindrical bore 22, which bores intersect one another in a zone medial of the length of the body as best illustrated in FIG. 5. The vertical bore 22 extends through a tubular boss 23 which extends vertically up wardly from the body 20, and may be integral with the latter as shown or otherwise secured thereto. The bore 22 on the lower end thereof intersects the horizontal bore 80, to be subsequently described, as shown in FIG. 5.

The jack assembly 16 further includes a generally cylindrical one-piece plunger 26 having a cylindrical top portion 27 and a cylindrical bottom portion 25. The plunger 26, intermediate its cylindrical ends, is machined or milled at diametrically opposite sides thereof to provide relatively flat and inclined locking surfaces 28 which taper divergently downwardly as shown in FIG. 5. Thus the entire plunger 26 is cylindrical except for the milled surfaces 28. The locking surfaces 28 are separated by cylindrical surfaces provided on the plunger 26 which, along with the cylindrical top and bottom portions 27 and 25, engage the cylindrical bore 22. Locking surfaces 28 are inclined at the same angle, which is preferably about 6", and the plunger 26 is provided diametrically across the surfaces 28 with a vertically elongated accommodation slot 29, for a purpose to be more fully described in brief to provide a transverse passageway for the reception of an axially movable actuating rod 36 to be subsequently described. The plunger 26 is also provided with an axial bore 30 extending downward from an upper closed end thereof as shown in FIG. 5.

The plunger 26 has a cylindrical spring can or like element 31 movable longitudinally in its bore 30, the can being formed with an internal closed bottom bore; and a biasing spring 32 is located in said bore, having its upper end in pressure contact with the top of plunger bore 30. The can 31 is held in body bore 22 by means of a transversely extending pin 33 located at the inner end portion of the plunger 26 as shown in FIG. 5. Pin 33 is engageable with the actuating rod 36 and is thus adapted to limit upward travel or movement of the post or plunger 26. Pin 33 also retains the plunger 26, spring can 31 and spring 32 of the post assembly together.

The top end of the plunger 26 is provided with a socket 34 which receives the end of the locator or locating button 17 (FIG. 2), being secured in socket 34 by suitable means such as a threaded connection, the button 17 thus forming an extension of plunger 26.

The horizontally elongated actuating rod 36 of the assembly is threaded on its inner end at 37, as shown in FIG. and a pair of longitudinally aligned and axially spaced cylindrical locking sleeves 38 and 39 are slidable in horizontal body bore 21 on opposite sides of plunger 26. The end 37 of rod 36 is threadedly connected in a threaded bore ofthe sleeve 39, and the end surface 40 of sleeve 39 adjacent the plunger 26 is inclined at a locking angle (such for example as 6) corresponding to the locking angle on the locking surface 28 of plunger 26. The sleeve 39 is formed with an elongated slot or keyway 41 (FIG. 4) which extends the entire sleeve length. A guide pin 42 carried by the body extends into the keyway 41 (FIG. 4) to prevent the sleeve 39 from rotating.

The other sleeve 38 has an internal smooth bore 43 through which the actuating rod 36 slidably extends; and the end surface 44 of sleeve 38 adjacent the plunger 26 is inclined at a locking angle (such for example as 6) corresponding to the locking angle on the locking surfaces of the plunger 26 and sleeve 39. Sleeve 38 is also formed with an elongated slot or keyway 45 (FIG. 4) which extends from the inclined locking end surface 44 past the midpoint in the length of sleeve 38, where body bore 21 is enlarged in a counterbore 21. A guide pin 46 carried by body 20 extends into the keyway 45 (FIG. 4) to prevent the sleeve 38 from rotating. An expansion plug or closing element 47 is received in one end of bore 21 to close it, as shown in FIGS. 4 and 5, and the opposite enlarged end of counterbore 21 is closed by a dust cover 48.

As appears in FIGS. 5 and 8, the actuating rod 36 has an integral head 50 on the outer end thereof provided with a set of peripheral recesses or scallops 51. A tubular head 52 is sleeved on the outer end of the acutating rod 36 and bears outwardly against head 50, which slides in body counterbore 21'. Fastener 53 threads into the head 52, being disposed in one of the recesses or scallops 51 to prevent relative rotation between the rod 36 and tubular head 52 as shown in FIG. 8. An elongated keyway or slot 54 (FIG. 4) formed in the tubular head 52 extends for the full length of the latter, and guide pin 55 carried by body 20 extends into keyway 54 (FIG. 4) to prevent head 52 and actuating rod 36 from rotating.

As shown in FIGS. 4 and 5, the left-hand locking sleeve 38 has a left-hand portion formed with parallel slots 56 on opposite sides of the rod 36. Rollers 57 are journaled for rotation in the slots 56 by hubs 58, the hubs being axially aligned with one another.

The head 52 has an end portion which also has spaced parallel slots 59 on opposite sides of rod 36, said slots being longitudinally opposed to and aligned with the respective slots 56 in the locking sleeve 38. Rollers 60 are journaled for rotation in the respective slots 59 by hubs 61, which hubs are aligned axially with one another. The head 52 is guided in its axial movement by the pin and slot arrangement 54, 55 which restrains it from rotation.

A fluid-operated piston-cylinder assembly 63 (FIG. 6), also referred to herein as the primary cylinder or assembly, includes a piston 64 which reciprocates in a bore or cylinder 65 communicating with the counterbored enlargment 21' of bore 21 in body 20 (FIG. 4). A cover plate 66 closes one end of the bore or cylinder 65 and has a passage 67 provided with a vent plug 67' (FIG. 7) for bleeding the jack assembly 16 of air when the system is initially used as will subsequently be explained.

The end of bore 65 opposite the cover plate 66, and which opens through an integral side boss 20' on body 20 is closed by another cover plate 68, and a pin 69 carried by plate 68 extends into the bore 65 and provides an abutment stop limiting the axial advance of piston 64.

Piston 64 is provided with an integral extension 70 which operates a camming wedge 71 in the form of a yoke, the legs 72 of which straddle the actuating rod 36 and are pinned to the piston extension 70 by a pin 73 as seen in FIGS. 4 and 6. The camming wedge 71 is disposed between the slotted end portions of the tubular head 52 and the locking sleeve 38; and the wedge 71 has inclined wedging surfaces 75 and 76 respectively facing and contacted by the pairs of the rollers 60 and 57, as clearly seen in FIGS. 4 and 5.

The wedge 71 is provided on its forwardly tapered end with a pin-shaped extension 77 which is aligned with the pin 69 carried by cover plate 68. A compression coil spring 78 encircles and pilots on the pins 69, 77 and is compressed between the cover plate 68 and the wedge 71, thus to urge the piston 64 and wedge 71 to a retracted position.

In use, when fluid pressure in cylinder 65 is relieved, the spring 78 returns the piston 64, downward as viewed in FIG. 4, retracting wedge 71. Accordingly, the locking sleeve elements 38 and 39 separate relative to one another to release the plunger 26 (FIG. 5) so that the plunger 26 may be adjusted. When fluid under pressure is delivered to cylinder 65 to move the piston 64 and camming wedge 71 toward stop 69, the wedge 71 in acting on the rollers 57 and 60 spreads the locking sleeve 38 and tubular head 52 apart to thus drive the locking sleeves 38 and 39 toward one another, so as to pinch or clamp upon and thus lock the plunger 26 in adjusted or clamping position. The pin or abutment stop 69 is positioned so as to limit the forward movement of piston 64 but will not interfere with the normal advance of the piston 64 to the point required for clamping the plunger 26 in adjusted or clamping positron.

FIG. 8 shows the tubular head 52 on actuating rod 36 as having angularly spaced peripheral scallops 51, the head of the fastener 53 being disposed in one of the scallops 51. Referring to FIG. 5, it will be obvious that the threaded connection at 37 between the actuating rod 36 and the locking sleeve 39 may be locked in an axially adjusted position where desired by turning the actuating rod 36 and then applying the fastener 53 so as to engage in an appropriate scallop 51.

A continuous elongated horizontal bore 80 is provided in the jack assembly body as best illustrated in FIG. 5. Bore 80 is located directly beneath the horizontal cross bore 21 and parallel to the latter. Bore 80 is closed at its left-hand end by a threaded plug 81 and at its right-hand end by a closure plate 82. Bore 80 serves as an elongated cylinder slidably receiving an elongated piston 83 which presents an elongated flat wedging surface 84. The cylinder or bore 80 and piston 83 form -a fluid motor which is also referred to herein as the secondary cylinder-piston assembly. The wedging surface 84 is wedgingly engageable upon movement of the piston 83 to the right as viewed in FIG. 5, with a correspondingly angled or slanted bottom surface 85 provided on the plunger 26. Thus the wedge piston 83 when in an operative position such as is illustrated in FIG. 5 affords a strong and positive support for the work-supporting plunger 26, once the latter has been gripped and clamped between sleeves 38, 39 in the manner described above.

An elongated coil compression spring 87, as guided by an elongated guide pin 87', telescopes into a bore in wedge piston 83 and acts to resiliently return the latter to the left upon cessation of operating pressure in cylinder 80.

FIG. 11 details a bleeder or ball check type valve unit, generally designated by the reference numeral 88, which is located in a cylindrical chamber 89. The valve unit 88 is in lateral communication through port 99 with the cylinder 80 on the pressure side of the piston 83 as shown in FIG. 5.

The ball check valve unit 88 may be threadedly engaged into the body bore 89 at a hex cap formation 91 (FIGS. 4, 7 and 11) which is integral with a tubular cage component 92 of the valve 88, and is received with substantial clearance in the cylindrical wall of bore 89, as best shown in FIG. 11. A bottom port of cage 92 which opens to bore 89, hence through bleeder line or port 99 with the cylinder bore 80, is normally closed by a sealing ball 93 urged downwardly by a relatively light force coil spring 94; and cage 92 opens at its top through a T-shaped passage 95 with passages 96, 97 in body 20. Passage 96 communicates through cover plate 66 (FIG. 4) with the hydraulic fluid admission port I00 in that plate. The function of ball check valve unit 88 is to bleed the cylinder in a normal unactuated or de-actuated position of the latters wedge piston 83, while at the same time preventing hydraulic oil from going from the primary piston-cylinder assembly 63 to the other or secondary piston-cylinder assembly 80, 83 until the sleeves 38, 39 have taken a pinching and clamping engagement with the plunger 26.

The valve 88 of FIG. 11 provides a bleeder and checking device for cylinder 80. The hydraulic fluid passes in one direction only through port 99 into bore 89, across the ball check valve 93 and out through passage 96 into cylinder 65. The hydraulic fluid will not flow in the opposite direction.

Another control or ball check valve unit is shown in detail in FIG. 12, being generally designated by the reference numeral 98. It is substantially identical to the valve unit 88 of FIG. 11, save for the fact that its control ball and spring are oriented oppositely from unit 88 in the vertical sense, and the spring loads the ball more heavily. Accordingly, corresponding reference numerals, primed, are applied to components of the unit 98 which correspond to components of the unit 88, and further description is dispensed with. Whereas in the bleeder valve 88 of FIG. 11 the spring 94 is a very light one and the ball acts away from the pressure, the spring 94 of unit 98, as disposed behind ball 93' is a strong one and acts toward the pressure. Hence, it is only after the sleeves 38, 39 have taken clamping engagement with main support plunger 26 as :shown in FIG. 5 that the ball check valve unit 98 comes into play; its T- shaped passage is then subject to oil pressure which overcomes the force of spring 94 and unseats ball 93. The internal space of ball check cage 92' is then communicated, as by lines or passages 102 and 99 and appearing in FIGS. 3 and 5. Wedge piston 83 is thereby forced to the right, as viewed in FIG. 5, to provide the desired rigicl support for the jack sub-assembly, at the end of the plunger 26. Thus a sequential action is provided in which plunger 26 is first pushed downwardly under the bias of spring 32 by the workpiece W to a desired height, the locking sleeves 38, 39 clamp plunger 26, and the wedge member 83 has under-buttressed the plunger 26.

Summarizing the foregoing, in operation, one or a plurality ofjack assemblies 16 are connected by means of the usual hydraulic lines 19 to a common pressure source 15 as illustrated in FIG. ll. Initially it is required to vent each ofthe jack assemblies 16 to remove all air therefrom. This is accomplished by loosening each plug 67 (FIG. 7) and operating the pressure system or source 15 as is well known in the art, with the result that pressurized hydraulic fluid is urged by the source 15 into the hydraulic system and displaces the air in the jack assemblies 16. The hydraulic fluid from source 15 enters each jack 16 through port 100 (FIG. 7) and then passes into passage 101 (FIGS. 4 and 7). The hydraulic fluid then pressurizes the lower end of cylinder 65 (FIG. 5) adjacent end cap 66 and moves the piston 64 upwardly as viewed in FIG. 4 to the locking position as described previously. Simultaneously hydraulic fluid occupies passage 96 but cannot escape therefrom since the spring 94 maintains the ball 93 of valve 88 on its seat in closed position as shown in FIG. 11. Simultaneously hydraulic fluid from passage 101 enters passage 90 which leads to valve 98 (FIG. 3, 7 and 12). The spring 94 acting against the pressure of the hydraulic fluid maintains the ball check valve 93' closed until after the pressure of the hydraulic fluid in passage 90 increases and overcomes the spring 94' thus urging the ball 93' off its seat. This occurs after the piston 64 has urged the locking sleeves 38 and 39 toward one another so as to lock the plunger 26 in clamping position.

Hydraulic fluid then passes through the open valve 98 to passage 102 (FIG. 7) and then into passage 99 (FIG. 3, and 7) and finally into cylinder 80 where the pressurized fluid exerts a force on the wedging piston 83 and moves it to the right (HO. 5) thereby exerting a force on the plunger 26.

When it is required to de-pressurize the system, the operator vents the pressure source 15. Thereafter, the hydraulic fluid in cylinder 80 is reduced in pressure with the result that spring 87 returns the wedging piston 83 to the left as viewed in FIG. 5. This results in the fluid exiting from cylinder 80 and returning towards the pressure source 15 via passages 99 and 89 in valve 88 where it overcomes the force of the relatively light spring 94. Thereafter the hydraulic fluid is allowed to pass to cylinder 65 via the open valve 88 and to thereafter return to the source 15 by means of passages 101 and 100 (FIG. 7).

I claim:

1. A work supporting device having a body provided with a pair of intersecting bores, a plunger slidable in one of said bores for engagement with a workpiece to sustain said piece rigidly, a locking device movable in the other bore to engage said plunger laterally from opposite sides and hold the latter in a workpiecesustaining position, and means other than said locking device movable laterally to support said plunger rigidly in said workpiece-sustaining position, said means comprising a wedge operable to engage and rigidly support and sustain said plunger in said workpiece-sustaining position, said locking device being operated for movement in said other body bore by a cam and follower unit, said wedge being fluid pressure-operated for said plunger-sustaining engagement.

2- The supporting device of claim, 1 in which said wedge is located and operable in a further bore in said body to engage and rigidly support and sustain said plunger in said workpiece-sustaining position.

3. The supporting device of claim 1, in which said locking device comprises a pair of clamp members slidable in opposite directions in said one body bore for said holding engagement with said plunger.

4. The supporting device of claim 2, in which said locking device comprises a pair of clamp members slidable in opposite directions in said one body bore for said holding engagement with said plunger.

5. The supporting device of claim 3, in which said cam and follower unit is fluid pressure-operated, said clamp members being simultaneously operated in said opposite directions by said cam and follower unit when energized.

6. The supporting device of claim 2, in which said cam and follower unit is fluid pressure-operated, said clamp members being simultaneously operated in said opposite directions by said cam and follower unit when energized.

7. The supporting device of claim 3, in which said cam and follower unit is fluid pressure-operated, said clamp members being simultaneously operated in said opposite directions by said cam and follower unit when energized.

8. The supporting device of claim 5, and further comprising valve means automatically controlling the application of fluid pressure to said cam and follower unit for operating said clamp members to occasion a holding of the plunger in said workpiece-sustaining position followed by operation of said wedge for its plungersustaining engagement.

9. The supporting device of claim 6, and further comprising valve means automatically controlling the application of fluid pressure to said cam and follower unit for operating said clamp members to occasion a holding of the plunger in said workpiece-sustaining position followed by operation of said wedge for its plungersustaining engagement.

10. The supporting device of claim 7, and further comprising valve means automatically controlling the application of fluid pressure to said cam and follower unit for operating said clamp members to occasion a holding of the plunger in said workpiece-sustaining position followed by operation of said wedge for its plunger-sustaining engagement.

11. A work supporting device having a body provided with a pair of intersecting bores, one of said bores being vertical and the other of said bores being horizontal, a plunger slidable in said vertical bore for engagement with a workpiece to sustain said workpiece rigidly, a pair of clamp members slidable in opposite directions in said horizontal bore to engage and downwardly press against opposite sides of said plunger and hold the latter against upward movement in a workpiecesustaining position, and means other than said clamp members movable laterally to support said plunger rigidly in said workpiece-sustaining position, said means comprising a wedge operable to engage and rigidly support and sustain said plunger in said workpiecesustaining position, said clamp members being simultaneously fluid pressure-operated for movement in said horizontal bore to prevent said plunger from moving upwardly, and said wedge being fluid pressureoperated for said plunger-sustaining engagement to prevent said plunger from moving downwardly.

12. The work supporting device defined in claim 11 wherein said plunger includes upper and lower end portions and having at opposite sides thereof a pair of upwardly converging and inclined surfaces starting near said lower end portion and extending towards said upper end portion.

13. The work supporting device defined in claim 12 wherein the bottom of said plunger has a tapered surface engageable with said wedge.

14. The supporting device defined in claim 13 wherein a cam and follower unit is provided for operating said clamp members, said cam and follower unit being fluid pressure-operated to operate said clamp members simultaneously in said opposite directions.

15. The supporting device defined in claim 14, and further comprising valve means automatically controlling the application of fluid pressure to said cam and follower unit for operating said clamp members to occasion a holding of the plunger in said workpiecesustaining position followed by operation of said wedge for its plunger-sustaining engagement. 

1. A work supporting device having a body provided with a pair of intersecting bores, a plunger slidable in one of said bores for engagement with a workpiece to sustain said piece rigidly, a locking device movable in the other bore to engage said plunger laterally from opposite sides and hold the latter in a workpiecesustaining position, and means other than said locking device movable laterally to support said plunger rigidly in said workpiece-sustaining position, said means comprising a wedge operable to engage and rigidly support and sustain said plunger in said workpiece-sustaining position, said locking device being operated for movement in said other body bore by a cam and follower unit, said wedge being fluid pressure-operated for said plunger-sustaining engagement.
 2. The supporting device of claim, 1 in which said wedge is located and operable in a further bore in said body to engage and rigidly support and sustain said plunger in said workpiece-sustaining position.
 3. The supporting device of claim 1, in which said locking device comprises a pair of clamp members slidable in opposite directions in said one body bore for said holding engagement with said plunger.
 4. The supporting device of claim 2, in which said locking device comprises a pair of clamp members slidable in opposite directions in said one body bore for said holding engagement with said plunger.
 5. The supporting device of claim 3, in which said cam and follower unit is fluid pressure-operated, said clamp members being simultaneously operated in said opposite directions by said cam and follower unit when energized.
 6. The supporting device of claim 2, in which said cam and follower unit is fluid pressure-operated, said clamp members being simultaneously operated in said opposite directions by said cam and follower unit when energized.
 7. The supporting device of claim 3, in which said cam and follower unit is fluid pressure-operated, said clamp members being simultaneously operated in said opposite directions by said cam and follower unit when energized.
 8. The supporting device of claim 5, and further comprising valve means automatically controlling the application of fluid pressure to said cam and follower unit for operating said clamp members to occasion a holding of the plunger in said workpiece-sustaining position followed by operation of said wedge for its plunger-sustaining engagement.
 9. The supporting device of claim 6, and further comprising valve means automatically controlling the application of fluid pressure to said cam and follower unit for operating said clamp members to occasion a holding of the plunger in said workpiece-sustaining position followed by operation of said wedge for its plunger-sustaining engagement.
 10. The supporting device of claim 7, and further comprising valve means automatically controlling the application of fluid pressure to said cam and follower unit for operating said clamp members to occasion a holding of the plunger in said workpiece-sustaining position followed by operation of said wedge for its plunger-sustaining engagement.
 11. A work supporting device having a body provided with a pair of intersecting bores, one of said bores being vertical and the other of said bores being horizontal, a plunger slidable in said vertical bore for engagement with a workpiece to sustain said workpiece rigidly, a pair of clamp members slidable in opposite directions in said horizontal bore to engage and downwardly press against opposite sides of said plunger and hold the latter against upward movement in a workpiece-sustaining position, and means other than said clamp members movable laterally to support said plunger rigidly in said workpiece-sustaining position, said means comprising a wedge operable to engage and rigidly support and sustain said plunger in said workpiece-sustaining position, said clamp members being simultaneously fluid pressure-operated for movement in said horizontal bore to prevent said plunger from moving upwardly, and said wedge being fluid pressure-operated for said plunger-sustaining engagement to prevent said plunger from moving downwardly.
 12. The work supporting device defined in claim 11 wherein said plunger includes upper and lower end portions and having at opposite sides thereof a pair of upwardly converging and inclined surfaces starting near said lower end portion and extending towards said upper end portion.
 13. The work supporting device defined in claim 12 wherein the bottom of said plunger has a tapered surface engageable with said wedge.
 14. The supporting device defined in claim 13 wherein a cam and follower unit is provided for operating said clamp members, said cam and follower unit being fluid pressure-operated to operate said clamp members simultaneously in said opposite directions.
 15. The supporting device defined in claim 14, and further comprising valve means automatically controlling the application of fluid pressure to said cam and follower unit for operating said clamp members to occasion a holding of the plunger in said workpiece-sustaining position followed by operation of said wedge for its plunger-sustaining engagement. 